ETHNOPHARMACOLOGICAL RELEVANCE: Aloysia polystachya (Griseb.) Moldenke (Verbenaceae) is a plant traditionally used as medicine for anxiety symptoms. This activity was confirmed in preclinical studies. However, its efficacy was never studied in human clinical trials.
AIM OF THE STUDY: We aimed to test the hypothesis that the herbal medicine of A. polystachya is superior to placebo for the treatment of anxiety-related symptoms in adults after 8 weeks.
PATIENTS AND METHODS: This was a randomized, double-blind, placebo-controlled, phase-2 clinical trial. Fifty-four adults with self-reported anxiety symptoms were randomly allocated to receive either capsules containing A. polystachya powdered leaves (300 mg, twice a day) or placebo (maltodextrin), for 8 weeks. The intensity of anxiety symptoms was assessed by the Hamilton Anxiety Ranking Scale (HAM-A) at baseline and after 2, 4 and 8 weeks. All analyses were adjusted for physical activity (assessed by the International Physical Activity Questionnaire [IPAQ], short version) and gender.
RESULTS: We confirmed the presence of acteoside (chromatographic analysis) and carvone and limonene (gas chromatography) as major constituents in our plant material. Only patients that received A. polystachya experienced a significant decrease in their HAM-A scores, with none or mild side-effects.
CONCLUSION: Administration of powdered leaves of A. polystachya, rich in acteoside, carvone and limonene, to adults with anxiety symptoms was significantly superior to placebo in decreasing HAM-A scores after 8 weeks. This finding confirms the ethnopharmacological use of this plant for anxiety symptoms.
Carmona F, et al. Aloysia polystachya (Griseb.) Moldenke (Verbenaceae) powdered leaves are effective in treating anxiety symptoms: A phase-2, randomized, placebo-controlled clinical trial. J Ethnopharmacol. 2019 Oct 5;242:112060. doi: 10.1016/j.jep.2019.112060. Epub 2019 Jul 4.